Procedures to treat vascular disease, such as angioplasty, atherectomy, and stenting, often create blood clots or dislodge material from the vessel walls. The clots (thrombi), and the dislodged material (emboli), enter the bloodstream and when large enough, occlude smaller downstream vessels blocking blood flow to tissue. Serious health risks, like stroke or even death, are created when the blockage occurs in the heart, lungs, or brain.
To combat these problems, several types of devices have been developed. Many of these devices employ the use of a filter, a basket type configuration, or a permeable sac to entrap the thrombi or emboli therein and these are often connected to the distal tip of a catheter or guidewire. Connecting these filters to a catheter or guidewire increases the overall profile of the device, which in turn diminishes its ability to negotiate through small vessels or tortuous anatomy. Consequently, it may be difficult or impossible to use these devices within vessels commonly found in the carotid artery and cerebral vasculature. Furthermore, many of these devices are incapable of preventing the material from escaping from the filter when the device is being removed from the body.
Many of these devices are also single functional. That is, their purpose is limited to the removal of emboli or thrombi from a patient's vasculature and they are incapable of being used for other purposes. One such purpose is the delivery of stents. Stent delivery to maintain passageways of blood vessels, biliary ducts, or other body lumens is well known. For example, stents are often deployed in an artery following a percutaneous transluminal coronary angioplasty (PTCA) procedure or a percutaneous transluminal angioplasty (PTA) procedure. The stent resists a tendency in the vessel to close, thus countering acute reclosure and plaque restenosis. A variety of stents and methods for delivering them are disclosed in the prior art. However, many of the typical prior art stents are incapable of being delivered and deployed within a bifurcated vessel.
One reason for this is that typically one branch of a bifurcated vessel is often larger in diameter than the other. Bifurcated stents and delivery systems have been developed in an attempt to overcome this problem. Many of them employ the use of multiple guidewires or multiple catheters, one for placement within each branch of the bifurcated vessel. However, entanglement of the wires often occurs because of the inability to control the movement of the wires. In addition, these devices often suffer from the same disadvantages above in that they often have large profiles, making them difficult to maneuver within small vessels and tortuous vasculature.